The present invention is related to a Graphical User Interface (GUI) and, in particular, to apparatus and method for easily and quickly identifying a group of data items from a number of data items displayed on a screen display by using a preselected graphical object (that is, a so-called landmark) which represents a desired group of data items, wherein the data items are stored in a storage device being operative via a programmable controller and are displayed on the screen display being operative via the programmable controller.
As well known in the art, the Graphical User Interface allows a user of a computer system to view data items (such as still or full-motion images, for example) on the screen display in a simple and user-friendly manner. The displayed items may be graphical or textual, and are stored in a memory storage of the computer system.
Using an input device and the GUI features, the user may arrange items into groups such that each item within a group is related to other items within that same group. The relationship among the group items may be temporal, contextual, etc., as preselected by the user.
Use of a system that enables collecting, organizing and browsing data in a graphic and zoomable space creates certain needs for navigating this data. Zooming, which allows the user to make on-screen objects larger and smaller, creates the need to organize information in new ways.
In a purely graphical space, data is organized geographically while in a zooming space, data may be organized by relative size. As more and more data objects are arranged geographically, it becomes hard to find particular objects in the space. Also as on-screen objects are zoomed out (made smaller), the objects appear to merge with each other and then disappear.
That is, as the displayed items (and the corresponding groups) increase on the screen display, it becomes more and more difficult for the user to identify individual items (objects) or even groups. Namely, in order to fit all of the items on the screen display, their size must decrease when new items are added. Clearly, at some point, the area of the display screen becomes too small for any intelligible viewing: the items become indistinguishable from each other, and the separation among the groups virtually disappears.
Under the above circumstances, when attempting to select a desired group or item from the group, the user may have to go through a "trial-and-error" selection process by increasing the size of the selected item (so-called "zooming in") by using a pointer of an input device such as a mouse, determining whether it is the desired item, reducing the size of the selected item (so-called "zooming out") if it is not what the user intended, and repeating this operation from the beginning with other items. It is apparent that the described selection procedure is inconvenient and time-consuming.
Another solution to the above viewing problem may include a concept of a so-called graphical universe. Namely, the graphical universe may include a virtually unbounded space in which the data items are located, while the screen display provides a viewing window into the universe (that is, displays a portion of the universe). By panning or scrolling in horizontal or vertical directions using the input device, the user may view the entire universe and keep adding new data items without reducing their size.
The disadvantage of this approach lies in the user's inability to view all of the items (or even groups) at the same time on the screen display.
With both geographic and zooming navigation needs, there is a need to develop various ways to help the user personalize, navigate and recognize its data.